The use of catheters for draining excess or infected body fluids from a body cavity or for infusing medication into a body cavity is well known. One use of the catheter may be to drain excess fluid. For example, the catheter may be used to drain urine from the kidney when there is an obstruction in the ureter. Another use of the catheter may be to drain fluid from an infected collection. For example, the catheter may be used to drain pus from an abdominal abscess. Once in position, the flexible distal portion at the end of the catheter may be altered to help to maintain the flexible distal portion within the body cavity. For example, one or more loops may be imparted at the distal flexible end of the catheter. These loops may be much larger than the hole through which the catheter is inserted. This may help to retain the catheter in the body cavity, which may help to prevent inadvertent removal of the catheter from the body cavity. Excess or infected fluid may enter a port or hole in the tubular member of the catheter and be withdrawn from the body cavity by aspiration or by gravity.
Typically, inserting the drainage catheter into the body cavity is done with the aid of an insertion tool, such as a stiffening cannula. The stiffening cannula may be inserted into the drainage catheter to support the drainage catheter and/or to at least partially straighten the loops at the distal flexible end of the catheter for placement in the body cavity. Typically, the stiffening cannula has a cylindrical shape with an outer diameter that is either larger than the inner diameter of the tip of the drainage catheter (which may be tapered) or smaller than the inner diameter of the body of the drainage catheter. A large gauge stiffening cannula may be unable to fit within the tip of the drainage catheter, which may result in a failure to straighten and/or support the tip of the drainage catheter. A small gauge stiffening cannula may not fully contact the inner surface of the body of the drainage catheter, which may result in a failure to support the body of the catheter. Failure to support and/or straighten the drainage catheter may result in damage to the drainage catheter caused by buckling and/or puncturing of the drainage catheter during insertion of the drainage catheter into the body cavity.